Tunnel construction.



RBRADLEY. TUNNEL CONSTRUCTION. APPLICATION IILBD SEPT. 21, 1912.

Patented June 24,1913.

2 SHEETS-SHEET 1.

v P. BRADLEY. TUNNEL CONSTRUCTION.

` APPLIOATIOK FILED SEPT. 21, 1.912. Patented June 24,

2 SHEETS-SHEET Z.

FRANK BRADLEY, or NEW YoRK, N. Y.

TUNNEL CONSTRUCTION.

Specicaton of Letters Patent.

Patented June 24,1913.

Application filed September 21, 1912.- Serial N o.y 721,563.

To all whom# may concern: Y

'Bep it known that I, FRANK BRADLEY, a citizen of the UnitedStates, residing in the A city of New York, in t-he countyf and State of New York, have invented certain new and useful Improvements in Tunnel Construction, of whichv the following is a specification. i

My invention is lparticularly intended to be`applied in the construction of tunnels through inclined rock strata where the planes of cleavage between the layers of rock intersect the `sides of the tunnel. In such cases there is constant danger of the sliding of rock into the tunnel excavation before the A side walls are complet-ed and many fatal accidents have occurred in such work from this cause.

The object of my improvements is to ob-V viate danger from thisV cause and provide a simple and etlicient means for insuring the safety of workmen engaged in tunnel construction under these conditions. Y

A form of construction illustrating an embodiment and method of practising my invention is shown in the accompanying drawings, Figure 1 -of which shows a vertical section of two perforations in rock and a rock supporting post inserted in` one of them; Fig. 2 shows a transverse section of an excavated portion of a tunnel with rock supporting arrangements in place; Fig. 3 shows a vertical longitudinal section of a portion of a tunnel looking in the direction of the arrows Fig. 3; Fig. @shows a vertical longitudinal section of a tunnel partly completed and Fig. 5 shows a transverse horizont-al section of the tunnel in the same stage of completion as shown in Fig. 4.

This preferred form, however, may be modied in ways thatwill readily occur to those skilled in the art.

In carrying my invention into effect I drill in advance of the tunnel construction, and along the lines of the proposed tunnel walls, openings, A, located in pairs on opposite sides of the tunnel, which extend from the earth surface B, to points below the rock level of the tunnel floor C. In these-openings, or bores, are placed cylinders, B, of suitable material, such as wrought iron, steel or other material, which eventually form supports against the outlying rock along the tunnel. In practice'I may use for these wrought iron pipe of a suitable size, say ten inches in diameter, and they may, if desired, be filled with cement and reinforced with rods when necessary to give greater rigidity. These extend upward from the bottom of the openings, or bores, A, z'. from below Vthe rock floor C of the tunnel, to such point as the nature of the work makes desirable.` In the case of arch roofed tunnels this will be approximately to the spring line of the arch or the top of the vertical tunnel side wall. These posts are placed with such frequency as will enable them to provide efficient support against the thrust of the outlying rock, the exact or desirablel distance apart being readily determinable in any given case in accordance with the nature of the rock through which the tunnel is being driven. The posts may vbe put down in convenient sections with lthreaded ends and sleeves 1n such manner that a joint will occur at the spring line of the arched tunnel. All the joints will be keyed to prevent separation except the one at the spring line to admit of disjointing the post at this point from above the rock surface and the placing thereon of a cap, al, over and upon which will be placed the transverse beam E. As in advance of the tunnel a pair of the posts, D, is approached, a shallow heading indicated at H is driven in the upper part of the tunnel exposing the posts, D, so. that they are uncovered. The transverse beam E, as a steel I beam is then secured to the tops of the pair of posts, D, D. To give greater rigidity braces F may be provided between the beam, E, and the posts, D, D. After the beam E is in place a roof supporting strut, G, based upon the beam, E, is put in place whereby rock falls from the roof are prevented. The

rock to be excavated to form the tunnel is then removed up to and between the posts, D, and to such distance beyond as may be deemed safe, approximating the next following pair of posts and the side walls and roof in the excavated part are4 then constructed in the usual manner. The posts, D, are rigidly held ,apart at their tops by the beams, E, and at their feet by the native rock intervening between the bases of the posts and prevent any fall or slide of rock into the tunnel pending the construction of the side walls and roof. Intermediate struts may be placed as occasion requires. Aft-er the side walls and roof are completed the strut, (hand, if desired, the beam E, are removed and the construction is continued in the same manner at theneXt pair of. posts.

In case it is desired to utilize the beams, E, as members of the completed structure vthese will be left in place.

In case of tunnel construction so near the surface as to require the making of an open out inthe first inst-ance the posts, D, may be of such length as to extend t-o, or more nearly to, the top of. the out, and they may if desired be made in sections screwed or otherwisev secured together, the uppermost of which can be removed if desired when the open cut above the tunnel is ready for filling in. In this case it is evident that the struts,

G, would not be employed andthe beams, E,may be located at such a'height as to be utilized as roof beams for the tunnel.

Having thus described my KYinvention, what I claim as new and desire to secure by Letters Patent is v l. The hereinbefore described improvement in the art of tunnel construction which consists in forming vertical perforations along the proposed side lines ofthe tunnel to points below the rock floor of the tunnel,

Copies of this patent may he obtained for five cents each, by addressing the inserting-posts, located in opposite pairs, in said perforations, extending the tunnel exciLVLtQIl to uncover the upper portions of a .consists in forming vertical Vperforations along the proposed side lines of the tunnel,`

inserting posts located in opposite pai-rs in said perforations, extending the tunnel ez;- eavation to uncover the upper portions of a pair of said posts, inserting a transverse Vbeam between said posts and a roof support based thereon and VVfinally completing the tunnel excavation between said posts.

In testimony whereof, I have hereunto subscribediny name, this 19th day of VSeptember A. D., 1912. v

t yFRANK BRADLEY. Witnesses: Y S. MEHRBACH,

JAMES A. LYNCH.

Washington, D. G. y

Commissioner of Patents, 

